The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Cetane number (CN) is a measurement of the ignition (i.e., combustion) quality of compression ignition (CI) fuel (e.g., diesel fuel) during compression ignition. In particular, CN affects the ignition delay of CI fuel (i.e., the time period between the start of injection of fuel into an CI engine and the start of combustion of an air/fuel mixture in the CI engine). CI fuels with higher CNs tend to have shorter ignition delays (and hence less time for the air/fuel mixture to form) than CI fuels with lower CNs.
CI fuel may be found with a wide range of CNs. For example, different countries require different minimum CNs and the diesel fuel grade at service stations may have a wide range of CNs. However, current CI engine systems are calibrated to use CI fuel with a certain CN. Operating an CI engine on CI fuel with a different CN may affect, for example, combustion, exhaust pressure, boost pressure, exhaust gas recirculation (EGR), and/or an air/fuel ratio. Further, burning CI fuel with a different CN than calibrated may increase, for example, emissions and/or noise.